Environmental exposures may increase the risk of chronic disease, either directly, or through their interaction with individual characteristics such as hormonal status, immune response, or genetic susceptibility. 1.) Data analysis continues in a study of risk factors for chronic renal disease, focusing on beverage consumption and occupational exposure to silica. Analysis of data from a related study of IgA nephropathy, a possibly immunologically-mediated subgroup of glomerulonephritis, is also continuing. Additional analyses have confirmed that a patients with IgA nephropathy often have a history of other kidney diseases that may have been unrecognized IgA nephropathy. Increased risk was seen in association with use of antibiotics, artificial sweeteners, especially in carbonated beverages, and with employment in selected industries with exposure to solvents and metals. 2.) Data analysis is also continuing in a cohort study in which women with prospective menstrual and reproductive data since 1935 were traced and interviewed to determine their risk of several diseases. Family history of breast cancer and increased cyclic hormone exposure were associated with increased breast cancer risk. Women with shorter cycles and women with more frequent cycles had the greatest risk of breast cancer. Early records on gynecological surgeries, use of hormones, and onset of menopause were reviewed to edited to correct inaccuracies. Standardized variable definitions are being developed, and analysis of data on colorectal neoplasms has been started.